Sky Lantern House

Sky Lantern House is an innovative full house refurbishment and extension project in South London for a young family of four. The project beautifully explores the core architectural principles of light, form, and craft, delivered with value and environmental responsibility. Two transformative voids, one through an articulated staircase, the other a clerestory ‘sky lantern’ at the rear, bring natural light and generous height to previously dark interior spaces. Expressed as an assemblage of stacked luminous boxes, the rear extension evokes the ethereal quality of ‘sky lanterns’ at night.

The simple external forms created internal complexity.

A restrained material palette was employed to unite form and space. A robust micro cement finish was used monolithically to the interior rear extension surfaces. Douglas fir timber was then specified extensively to floors, stair and study room bringing a natural warmth and softness to the space, a deliberate contrast to the more industrial external glazed finish. 

The stair void is defined with warm natural Douglas Fir, but is equally and rigorously detailed. Wide format planks sandwich a discreet steel cantilevered stair structure. The warm timber finish is used extensively to the ground floor living spaces and defines the study both internally (desk and floor) and externally.

Operational carbon is reduced with an ambitious approach to technical design. Environmentally the project is designed beyond required thermal performance, achieving a 27% improvement over regulatory U-values (heat loss calculations). High performance glazing was balanced with particularly high levels of insulation to solid walls and roofs, and SAP calculations were produced to show the extension had reduced CO2 emissions versus a notional extension.